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The mkiv Supra Owners Club

Engine wont start after rebuild (Fuel?)


veilsideTT

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Hi all.

 

Finally got to the "turning of the key" point today after rebuilding my TT engine (Shortblock Installed)

 

Unfortunatly she wouldnt fire. Engine turns over fine though.

I went straight for the fuel side of things and after a while i managed to trace the problem to the fuel pump.

 

With the ignition on, the fuel pump isnt pumping at all. But 12V across it and she pumps. I bypassed the Immobiliser cuts down at the ECU just incase it was the alarm (very dodgy old toyota alarm) cutting the fuel. but no joy there.

 

Any ideas anyone as ive about given up for the day on it now!

 

Scott

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Not something i have checked but i can have a look at it. I take it i should be working back from the Pump to the ECU then?

 

If i have nothing (Voltage) going into the Fuel ECU then where does the wiring go before that? straight to the ECU?

 

Could a bad earth that i have installed cause a problem like this? Are there any other places where Toyota would have installed cuts in Fuel Wires for the Immobiliser apart from at the ECU?

 

Cheers

Scott

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good point if thats true.

 

But i have no fuel pumping through even when i crank (Took the delivery pipe off the fuel filter)

 

Think i have checked the wrong pins on ECU for the Fuel Pump. I looked at the EFI pins not the Fuel Pump pins.

 

Will have to check that tommorow now.

 

Scott

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Simon's right. When the ignition is switched on, the fuel pump will work for a second or so, then stop, until the engine is cranked.

Check the two thick wires at the pumps ECU, (blue/orange and Blue/red). You should have 12v ignition input on one, and anything from 5v upwards on the other. (yes I know it should be 9v, but I've tested this wire on a number of cars and it's always lower than 9v at idle).

 

You can cut the two wires and join them together, to get it running. This is the 12v mod on mkiv.com.

Personally, I use a relay controlled from the pumps ECU, to make sure the pump stops pumping should the engine stop...

 

HTH

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Without actually testing each side of the Pump ECU i cant be 100% sure but i doubt there is any current going to the Pump ECU.

 

Only reason i say this is because with the delivery pipe disconnected (At Fuel Filter) and the engine cranking i have not got any fuel comming through.

 

But if i put 12V battery onto the pump it flows fuel out of the delivery pipe!

 

scott

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ok,

 

Ive checked all fuses and there fine.

Ive checked the crank position sensor, that is all connected and ok.

Ive looked all around the enigine for loose connnectors or earths, no problems there

 

I tested the current at the Main ECU for the fuel pump (pins 21&22). Nothing there on ignition or crank. that rules out anything past there like Fuel Pump ECU and Fuel Pump.

 

What more can i do! Its driving me mad!

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Problem Solved!!!

 

Checked all the Connecters down at the ECU.

 

There is one plug (Orange on on the firewall) that has like a plastic arm that has to be pulled down to lock the plug in place.

I had not pulled it down. :zzz:

There must be some sort of mechanisim that makes the connecton when you pull the lever down!

 

She started straight the way!!!!

 

Thanks all for your help. Sorry if my stupid mistake wasted your time everyone

 

Scott

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